true nature; real character
Used almost exclusively in the set phrase 得体が知れない (something of unknown or suspicious nature). Rarely appears outside this expression.
That man is somehow suspicious; I can't figure him out.
この生き物は得体が知れなくて気味が悪い。
This creature is creepy because its true nature is unknown.
Standard kanji spelling. Almost always used in the phrase 得体が知れない.
The word developed from 為体, formerly read えいたい, meaning a person’s appearance, condition, or true character. 得体 is a later spelling of the contracted form えたい.