ichidan verb, intransitive verb
get too skinny; become emaciated
Describes losing weight to an unhealthy or extreme degree, often with a negative connotation.
病気で痩せこけてしまった。
He became emaciated due to illness.
彼女は最近痩せこけて見える。
She looks too skinny lately.
Standard kanji spelling.
Kana spelling is common in casual writing.
痩せる is the general verb for losing weight or becoming thin, while 痩せこける specifically implies an unhealthy, extreme thinness.
Compound of 痩せる (yaseru, 'to lose weight') and こける (kokeru, a suffix meaning 'to become completely' or 'to fall into a state'). The exact historical derivation of the suffix is uncertain.