expression, noun
Refers to the person who leads or represents a household, often the patriarch or matriarch. A formal, somewhat literary term.
彼は一家の長として家族を支えている。
As the head of the family, he supports his household.
世帯主 is an administrative term for the head of a household as registered in official documents, whereas 一家の長 carries a more traditional or familial nuance.
Compound of 一家 (いっか, 'one family') + の (possessive particle) + 長 (ちょう, 'head, chief'). The reading いっか follows standard rendaku avoidance.