Synonyms in the same form
Noun plural
Mark
marks, signals, symbols, signatures, tokens, symptoms, notes, vestiges, badges, markings, labels, trails, emblems, types, traces, characteristics, motions, characters, miracles, indexes, beacons, devices
Omen
omens, warnings, auguries, prognostics, portents, harbingers, wonders, forebodings, forerunners, prodigies, auspices, foretokens, portenders
Indication