modified noun; head noun
Linguistics term for the noun that is modified by a preceding clause or phrase, e.g., the noun after a relative clause.
In 'the book I bought yesterday,' 'book' is the modified noun.
修飾語 is a modifier (adjective, adverb, etc.), while 被修飾名詞 is the noun being modified.
連体修飾 refers to the whole modifying clause/phrase, whereas 被修飾名詞 is specifically the noun that receives that modification.
Compound of 被 (ひ, 'receiving') + 修飾 (しゅうしょく, 'modification') + 名詞 (めいし, 'noun'). A calque from Western linguistic terminology.