Roman candle, aid to navigation, alarm, amber light, balefire, beacon, beacon fire, beat the drum, bell, bell buoy, blinker, blue peter, buoy, caution light, contemplate, dekko, dip, examine, exchange colors, eye, eyeful, flag, flag down, flare, flash, fleer, fog bell, fog signal, fog whistle, foghorn, give a signal, give the eye, give the nod, give the once-over, glad eye, glance, go light, gong buoy, green light, hail, hail and speak, half-mast, hard look, heliograph, high sign, hoist a banner, inspect, international alphabet flag, international numeral pennant, kick, leer at, leering look, look-in, look, look over, lustful leer, make a sign, marker beacon, nod, nudge, ogle, ogle at, parachute flare, peruse, pilot flag, poke, police whistle, pore, pore over, preview, prospect, quarantine flag, radio beacon, raise a cry, red flag, red light, regard, rocket, sailing aid, salute, sardonic grin, scene, scornful laugh, scrutinize, semaphore, semaphore flag, semaphore telegraph, sidelong look, sight, sign, signal, signal beacon, signal bell, signal fire, signal flag, signal gong, signal gun, signal lamp, signal light, signal mast, signal post, signal rocket, signal shot, signal siren, signal tower, signalize, size up, sly look, smirk, sneer, snicker, snigger, snort, sound an alarm, sound the trumpet, spar buoy, speak, stop light, survey, take a long, take stock of, the eye, the nod, the wink, touch, traffic light, traffic signal, unfurl a flag, vet, view, watch fire, wave, wave a flag, wave the hand, white flag, wigwag, wigwag flag, wink, yellow flag