老婆 (lǎo pó) is an intimate and informal word for wife. 老 is an affectionate prefix and 婆 refers to an older woman or grandmother in other contexts. Together, 老婆 is similar to missus or the wife in English - warm and casual. Its male counterpart is 老公 (lǎo gōng, husband, informal). These terms are preferred in everyday speech between couples or close friends, while 妻子 (qī zi) and 丈夫 (zhàng fu) are more formal/written.