TOEFL Vocabulary: Advanced reasoning and argument 40 hard-tier words, each with a short plain-English definition, followed by a quick quiz to check what stuck.
Test Ninjas Research · Updated October 1, 2026
Precise words for evaluating ideas: corroborate, refute, concede, tenable, equivocal, salient. They let an academic text distinguish a strong claim from a cautious one, and they reward careful readers who notice the difference.
Most useful for: Read an Academic Passage · Listen to an Academic Talk · Academic Discussion .
Advanced reasoning and argument is one of the hard themes in our
TOEFL vocabulary list , where you can also find how the tiers work.
The 40 words Advanced reasoning and argument — Hard tier # Word Meaning Tier 1 ambiguous open to more than one reasonable meaning Hard 2 anomalous unexpected in relation to an established pattern Hard 3 appraise to judge quality after close examination Hard 4 axiom a principle accepted as a starting point Hard 5 causal involving one event producing another Hard 6 caveat a warning about a limit or condition Hard 7 coherent forming a clear and connected whole Hard 8 concede to acknowledge a point made by another person Hard 9 confound to make an effect hard to attribute to one cause Hard 10 consensus general agreement among a group Hard 11 contradict to state or show the opposite of a claim Hard 12 corroborate to strengthen a claim with independent evidence Hard 13 critique a careful evaluation of strengths and weaknesses Hard 14 deductive moving from general rules to a particular conclusion Hard 15 delineate to describe the exact limits or features Hard 16 discrepancy a difference between results that should agree Hard 17 equivocal unclear or open to conflicting interpretations Hard 18 fallacy an error in the logic of an argument Hard 19 generalize to apply a finding beyond the cases observed Hard 20 hypothetical based on an imagined situation for analysis Hard 21 inductive moving from particular cases toward a general rule Hard 22 juxtapose to place things side by side for comparison Hard 23 nuance a subtle difference in meaning or judgment Hard 24 paradox a seeming contradiction that may contain truth Hard 25 plausible reasonable enough to be believed Hard 26 presuppose to take an idea for granted in advance Hard 27 reconcile to make conflicting ideas fit together Hard 28 refute to show that a claim is mistaken Hard 29 rigorous careful and strict in method or reasoning Hard 30 salient especially noticeable or important Hard 31 scrutinize to examine with close and critical attention Hard 32 scope the range of subjects covered by a study or claim Hard 33 synthesis a new whole formed from several ideas Hard 34 tentative offered with uncertainty and open to change Hard 35 tenable able to be defended with sound reasons Hard 36 undermine to weaken support for a claim or system Hard 37 unequivocal leaving no reasonable doubt about meaning Hard 38 untenable impossible to defend with good evidence Hard 39 soundness the quality of a deductive argument with valid reasoning and true premises Hard 40 defensible able to be supported by sound reasons Hard
Self-check: match the meaning Cover the table above. Here are 8 of the 40 advanced reasoning and argument words, starting with ambiguous : choose the word each definition describes.
open to more than one reasonable meaning ambiguous deductive refute tenable Show answer A. ambiguous
a warning about a limit or condition generalize caveat synthesis defensible Show answer B. caveat
to state or show the opposite of a claim paradox untenable contradict causal Show answer C. contradict
a difference between results that should agree rigorous appraise consensus discrepancy Show answer D. discrepancy
moving from particular cases toward a general rule inductive tentative concede delineate Show answer A. inductive
to take an idea for granted in advance soundness presuppose critique hypothetical Show answer B. presuppose
to examine with close and critical attention axiom fallacy scrutinize plausible Show answer C. scrutinize
to weaken support for a claim or system confound nuance salient undermine Show answer D. undermine
Using advanced reasoning and argument words on the test In Read an Academic Passage, axiom and contradict often carry a paragraph's main point, so check how each one connects to the sentence before it. In Listen to an Academic Talk, a speaker may define fallacy or plausible on the spot; note the definition, not just the word. In the Academic Discussion, scope and soundness can make your position precise; use them in a sentence that also gives a reason. Other hard themes
Previous ← Academic and campus administration Next Advanced research and measurement → Frequently Asked Questions How many words are in the advanced reasoning and argument list? + 40, from ambiguous to defensible, all in the hard tier of our TOEFL list. The self-check quiz on this page tests 8 of them, beginning with ambiguous.
Where do advanced reasoning and argument words appear on the TOEFL? + Language like this is most useful in Read an Academic Passage, Listen to an Academic Talk and Academic Discussion. Treat them mainly as recognition vocabulary; passages usually give enough context for the specialist terms.
Which advanced reasoning and argument words should I learn first? + Start with caveat (a warning about a limit or condition); discrepancy (a difference between results that should agree); presuppose (to take an idea for granted in advance). In Read an Academic Passage, axiom and contradict often carry a paragraph's main point, so check how each one connects to the sentence before it.