inattentive

the word inattentive is a straightforward english formation built upon the existing adjective attentive. the prefix in-, from latin, functions as a negative particle, directly reversing the meaning. the core adjective attentive entered english in the late 14th century from old french attentif, which itself descended from latin attentus, the past participle of attendere ("to stretch toward, give heed to"). this latin verb is a compound of ad- ("to") and tendere ("to stretch"). therefore, the etymological logic of inattentive is a clear negation: "not in a state of stretching one's mind toward something," which perfectly captures the modern sense of being careless or not paying heed.

Structure: in (not) + attentive (paying attention) in- is a Latin prefix meaning "not" or "without". attentive is an english adjective derived from the latin verb attendere, meaning "to give heed to".