A pair of absorbent underpants worn by children during potty training; specifically (in later use) a nappy or diaper with an elasticated waistband, which may be pulled up and worn like underpants.
Origin
1920s; earliest use found in Decatur (Illinois) Herald.
Definition of training pants in US English:
training pants
noun
US
A pair of absorbent underpants worn by children during potty training; specifically (in later use) a nappy or diaper with an elasticated waistband, which may be pulled up and worn like underpants.
Origin
1920s; earliest use found in Decatur (Illinois) Herald.