You already know 大, a person standing with arms spread wide. 夫 draws that very same figure with one extra stroke across the top. The ancient dictionary Shuōwén Jiězì explains that stroke as a hairpin: a young man's coming-of-age ceremony, at twenty, pinned his hair up under a cap for the first time, marking him a grown man — and, later, the grown man of the house.
A piece of culture
A "zhang-tall" man The word for "husband", 丈夫 (zhàngfū), literally means "a zhang-tall man". Shuōwén Jiězì explains why: in Zhou-dynasty measurements ten chǐ made one zhàng, and a grown man stood close to eight chǐ tall — near enough to a full zhàng that "zhang-tall" simply became the word for a grown man, then for a husband. The same logic gives Chinese 大丈夫 (dàzhàngfū), "a real man" — someone who lives up to his own measure.
Use it in a real word
丈夫
zhàngfū · zoeng6 fu1
husband — literally "a zhang-tall man"; you already know 夫