Is memorising GRE word lists worth it, or is there a better use of the time?

Partly worth it, and most people do it in the least efficient way available — flashcards with one-word definitions, learned in isolation, in alphabetical order.

The verbal section tests words in context, and a one-word gloss frequently is not enough to choose between two options that both roughly fit.

Why isolated definitions fail

Take a word you half-know. You remember it means something like "brief". That is enough to recognise it and not enough to distinguish it from three other options that also mean something like "brief" but differ in register, connotation or what they attach to.

Text-completion questions are built on exactly those distinctions. The gap needs a word that is not merely in the right area but carries the right tone and fits the sentence's logic.

So learning the area is necessary and insufficient.

What works better

Learn words in sentences, not as pairs. Write or find one sentence using the word correctly, and learn that. The sentence carries the register and the grammar along with the meaning.

Group by connotation, not alphabet. Positive, negative, neutral. Being able to say instantly that a word is disapproving eliminates options faster than a precise definition does, and many questions are decided on that alone.

Learn roots for the words you will not meet. You cannot memorise everything. Knowing that bene is good, mal is bad, loqu is speaking, greg is group lets you make an informed guess at a word you have never seen, which is what actually happens on test day.

Read material that uses the words. Dense non-fiction — serious journalism, academic writing, long-form essays. Slower than flashcards and it builds the contextual sense that flashcards cannot.

Use the sentence's structure

This is the part students skip, and it often matters more than vocabulary.

Text completions contain signal words that tell you the direction of the gap before you consider any option:

• Although, despite, however, yet, nonetheless → the gap contrasts with what came before
• Because, since, therefore, thus, consequently → the gap agrees with it
• Not only, moreover, indeed, furthermore → the gap extends it

Decide the direction first, predict your own word, then look. With a two-blank or three-blank question, do the blank you are most confident about first and let it constrain the others.

A student with moderate vocabulary and good structural reading beats one with a large vocabulary and no method, fairly consistently.

How much time to spend

If your verbal score is already decent, more word lists have poor returns. Work on reading comprehension and the structural signals instead.

If you are losing marks because you genuinely do not know the words, then yes, learn words — but in sentences, grouped by tone, alongside reading that uses them.