sign
n
1 clue, evidence, gesture, giveaway, hint, indication, manifestation, mark, note, proof, signal, spoor, suggestion, symptom, token, trace, vestige
2 board, notice, placard, warning
3 badge, character, cipher, device, emblem, ensign, figure, logo, mark, representation, symbol
4 augury, auspice, foreboding, forewarning, omen, portent, presage, warning, writing on the wall
vb
5 autograph, endorse, initial, inscribe, set one's hand to, subscribe
6 beckon, gesticulate, gesture, indicate, signal, use sign language, wave
sign away
abandon, dispose of, forgo, give up all claim to, lose, relinquish, renounce, surrender, transfer, waive
sign on , up
1 contract with, enlist, enrol, join, join up, register, volunteer
2 employ, engage, hire, put on the payroll, recruit, take into service, take on, take on board (informal)