grown
Word family
Synonym discussion
Sense: adjective/1
All five words describe someone who is no longer a child, but they differ in register, scope, and typical usage. 'Grown' is an attributive adjective that appears mainly before nouns ('grown children'), and carries a warm, family-oriented tone. 'Adult' is the most neutral and formal term — it functions as both adjective and noun, and is preferred in legal, medical, and educational writing. 'Mature' goes beyond physical age to describe emotional or intellectual development; a person can be legally an adult but described as 'not very mature.' 'Grown-up' is the informal everyday word that young children use ('when I'm a grown-up'), and can also be a noun. 'Fully-grown' emphasises that an animal or person has completed physical development — it is the natural choice for describing pets and wildlife ('a fully-grown golden retriever'). Choosing among them depends on whether you need formality (adult), warmth (grown), or precision about physical development (fully-grown).
Common collocations
Etymology
'Grown' comes from the past participle of the verb 'grow,' which traces back to Old English 'grōwan' (to grow, flourish). That word comes from Proto-Germanic '*grōaną,' which in turn comes from Proto-Indo-European '*ghre-' (to grow, become green). The adjective sense — meaning having reached full development — appeared in English around the 14th century.