TOEFL Vocabulary: Earth and physical systems 40 medium-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
Erosion, sediment, pressure, velocity, evaporation: the vocabulary of geology, weather and basic physics. These words tend to appear inside step-by-step explanations, so recognizing them helps you track the sequence a lecturer is describing.
Most useful for: Complete the Words · Read an Academic Passage · Listen to an Academic Talk .
Earth and physical systems is one of the medium themes in our
TOEFL vocabulary list , where you can also find how the tiers work.
The 40 words Earth and physical systems — Medium tier # Word Meaning Tier 1 atmosphere the layer of gases around a planet Medium 2 circulation movement around a system or path Medium 3 deposit to leave material on a surface Medium 4 erosion the gradual removal of soil or rock Medium 5 fault a break in rock along which movement occurs Medium 6 fossil preserved remains or traces of ancient life Medium 7 friction resistance when surfaces move against each other Medium 8 geology the study of Earth's materials and history Medium 9 glacier a large mass of ice that moves slowly Medium 10 gravity the force pulling objects toward one another Medium 11 groundwater water held below the land surface Medium 12 humidity the amount of water vapor in the air Medium 13 layer a level of material above or below another Medium 14 mass the amount of matter in an object Medium 15 mineral a natural solid with a characteristic composition Medium 16 particle a very small piece of matter Medium 17 pressure force applied per unit of surface area Medium 18 radiation energy traveling as waves or particles Medium 19 react to change through interaction with another substance Medium 20 sediment material carried and laid down by water or wind Medium 21 surface the outer or upper part of something Medium 22 temperature a measure of how hot or cold something is Medium 23 thermal related to heat Medium 24 tectonic related to movement of Earth's crustal plates Medium 25 terrain the physical features of land Medium 26 vapor a substance in its gas form Medium 27 velocity speed in a given direction Medium 28 volcano an opening where molten rock can reach the surface Medium 29 wave a moving disturbance that carries energy Medium 30 weathering the breaking down of rock at the surface Medium 31 compress to press into a smaller space Medium 32 absorb to take in energy or material Medium 33 density the mass contained in each unit of volume Medium 34 evaporate to change from liquid to gas Medium 35 filter to separate material by passing through a barrier Medium 36 fluid a substance that flows Medium 37 reflect to send light or sound back from a surface Medium 38 rotate to turn around a center Medium 39 solar related to the sun Medium 40 transmit to send energy or information through a medium Medium
Self-check: match the meaning Cover the table above. Here are 8 of the 40 earth and physical systems words, starting with atmosphere : choose the word each definition describes.
the layer of gases around a planet atmosphere mass volcano filter Show answer A. atmosphere
preserved remains or traces of ancient life react fossil density transmit Show answer B. fossil
water held below the land surface tectonic rotate groundwater fault Show answer C. groundwater
a very small piece of matter wave deposit gravity particle Show answer D. particle
the outer or upper part of something surface evaporate geology mineral Show answer A. surface
a substance in its gas form solar vapor layer sediment Show answer B. vapor
to press into a smaller space erosion radiation compress terrain Show answer C. compress
a substance that flows glacier thermal weathering fluid Show answer D. fluid
Using earth and physical systems words on the test In Read an Academic Passage, erosion and groundwater 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 radiation or terrain on the spot; note the definition, not just the word. In Complete the Words you see only the first letters of a word, so practice spelling absorb and solar as well as knowing what they mean. Other medium themes
Previous ← Living systems and ecology Next History, language, and culture → Frequently Asked Questions How many words are in the earth and physical systems list? + 40, from atmosphere to transmit, all in the medium tier of our TOEFL list. The self-check quiz on this page tests 8 of them, beginning with atmosphere.
Where do earth and physical systems words appear on the TOEFL? + Language like this is most useful in Read an Academic Passage, Listen to an Academic Talk and Complete the Words. These are general academic words worth recognizing quickly and using when they fit.
Which earth and physical systems words should I learn first? + Start with fossil (preserved remains or traces of ancient life); particle (a very small piece of matter); vapor (a substance in its gas form). In Read an Academic Passage, erosion and groundwater often carry a paragraph's main point, so check how each one connects to the sentence before it.