| insubstantial(imaginary, fictional) |
| lying(adjective, fake, counterfeit, sham, phony) |
| manufactured(adjective, fake, counterfeit, sham, phony) |
| mendacious(adjective, fake, counterfeit, sham, phony) |
| misleading(adjective, fake, false, counterfeit, sham) |
| mythological(adjective, mythical) |
| offhand(adjective, adverb, free, impulsive, spontaneous) |
| pretend(adjective, fake, false, counterfeit, sham) |
| pseudo(adjective, fake, unusual, strange, counterfeit) |
| spontaneous(adjective, free, casual, unrehearsed, improvised) |
| theoretical(fantastic, unreal, fictitious, invented, speculative) |
| unprepared(adjective, free, spontaneous, unrehearsed, improvised) |
| unrehearsed(adjective, adverb, free, impulsive, spontaneous) |
| untruthful(adjective, fake, counterfeit, sham, phony) |
| visionary |
| Utopian |
| according to pleasure(expression, informal, impulsive, unplanned, extemporaneous) |
| ad-lib(adjective, adverb, free, casual, impulsive) |
| ad hoc(expression, free, informal, casual, unrehearsed) |
| ad lib(expression, free, informal, snap, unrehearsed) |