ch'in n. uncountable + Add to list C2 Proficiency US //ˈtʃɪn// UK //tʃˈɪn// chin Archaic Informal Slang Synonyms Synonyms kukikuki chinmentum Idioms3 entries01keep one's chin upTo remain positive and cheerful.02lead with one's chinTo behave without caution; to make oneself vulnerable.03take on the chinTo accept without flinching or complaining.