The Chinese word for step-father is
继父

jì fù

Chinese Definition

Components
继
1. Simplified form of 繼
父
1. father
父親 (fùqīn) - (formal) father
父母 (fùmǔ) - parents; father and mother
父子 (fùzǐ) - father and son
父女 (fùnǚ) - father and daughter
父輩 (fùbèi) - one's father's generation
家父 (jiāfù) - (humble) my father
生父 (shēngfù) - biological father
養父 (yǎngfù) - adoptive father
繼父 (jìfù) - stepfather
天父 (tiānfù) - (Christianity) Heavenly Father
國父 (guófù) - father of a nation; (specifically) Father of the Republic (Sun Yat-sen)
雜交水稻之父 (zájiāo shuǐdào zhī fù) - (specifically) Father of Hybrid Rice (Yuan Longping)
(ant, zh, 母)
2. (Used to address a male elder member of a family.)
祖父 (zǔfù) - paternal grandfather (one's father's father)
伯父 (bófù) - paternal uncle (father's elder brother)
叔父 (shūfù) - paternal uncle (father's younger brother)
岳父 (yuèfù) - father-in-law (wife's father)
舅父 (jiùfù) - maternal uncle (mother's brother)
姨父 (yífù) - maternal uncle (husband of mother's sister)
姑父 (gūfù) - paternal uncle (husband of father's sister)
(ant, zh, 母)
3. (literary, respectful) old man; elderly man
漁父fǔ (yúfǔ) - old fisherman
田父fǔ (tiánfǔ) - old farmer
4. (literary) Alternative form of 甫 ((honorific suffix used after a man's name;) courtesy name)
梁父fǔ山（梁甫山） (Liángfǔshān (Liángfǔshān)) - Mount Liangfu (alternately, Mount Liangfu) (in Shandong, China)