Neglectful means failing to give the care that is owed. A neglectful parent, neglectful of his duties, neglectful care.
The duty is what makes it a fault: you can only be neglectful of something you were responsible for, which is why the word appears in law and in complaints rather than in ordinary description. Neglect as a legal category is failing to act rather than acting badly. Note that the Latin means not to pick up.
1adjectiveneglectfulFailing to give the care that is owed.
“The neglectful owners left their dog without food or water for days.”
neglectful is a quality of failing in care.
Neglect plus -ful, from Latin neglegere — nec plus legere, to pick up or choose. Elect and collect come from the same choosing.
Proto-Indo-European
*leǵ-
Latin
neglēctus
Middle English
neglecten
English
neglect
English, today
neglectful
Built from
From neglect + ful. neglect The verb is Middle English neglecten, derived from Latin neglēctus, perfect passive participle of neglegō (“to make light of, disregard, not to pick up”), itself from nec (“not”) + legō (“to pick up, select”). The noun is from neglēctus (“neglect”). 1460, the noun in 1588.
Etymology from Wiktionary, CC BY-SA