| Word | Definitions | Synonyms |
|---|---|---|
| incessantly | (adverb) invariably | Synonyms: always, constantly, forever, perpetually |
| (adverb) with unflagging resolve | Synonyms: ceaselessly, continuously, endlessly, unceasingly, unendingly | |
| incestuously | (adverb) by incest | - |
| insincerely | (adverb) without sincerity | - |
| sincerely | (adverb) with sincerity; without pretense | Synonyms: truly, unfeignedly |
| (adverb) written formula for ending a letter | Synonyms: sincerely yours |