upkeep - maintenance, preservation⏎
unique - special, unusual, inimitable, one of a kind⏎
sue - litigate, claim damages in court⏎
zenith - summit, top, peak⏎
rival - competitor, contender⏎
theory - idea, opinion, supposition⏎
vendee - buyer, property purchaser⏎
salary - wages, pay, earnings⏎
slice - a share, portion, piece, part of something⏎
unscrupulous - dishonest, not fair, not honest, without morals,⏎