| Word | Definitions | Synonyms |
|---|---|---|
| inboard | (adjective) located within the hull or nearest the midline of a vessel or aircraft | - |
| inborn | (adjective) normally existing at birth | Synonyms: connatural, inbred |
| (adjective) present at birth but not necessarily hereditary; acquired during fetal development | Synonyms: congenital, innate | |
| inbound | (adjective) directed or moving inward or toward a center | Synonyms: inward |