thin as a rail

Idioms and Phrases

Very slender, as in I do not know why she's dieting; she's thin as a rail already . This simile, which uses rail in the sense of “a narrow bar,” has largely replaced such other versions as thin as a lath or rake , although the latter is still common in Britain. [Second half of 1800s]

Related Words

• bony
• gaunt
• scrawny
• skeletal
• skinny