The term 'give the thumbs-up' is a gesture of approval or agreement. It is often used to signify that something is good or acceptable. The crossword solutions for this term are ASSENT (6 letters), OKAY (4 letters), and SAYYES (6 letters). ASSENT means to agree to something, OKAY is an informal way of saying yes, and sayyes is another way of expressing agreement. All three words can be used to indicate that someone is giving the thumbs-up.