Definition of undershorts in English:
 undershorts
plural nounˈʌndəʃɔːtsˈəndərˌʃɔrts
North American Underpants.
 Example sentencesExamples
-  I've slept in my undershorts, but I was too tired to change out of my shirt last night.
 -  Wandering the streets wearing only his undershorts and trying to find help, he is spotted by two young women who try to help him.
 
  Definition of undershorts in US English:
 undershorts
plural nounˈəndərˌSHôrtsˈəndərˌʃɔrts
North American Underpants, especially those worn by men or boys.
 Example sentencesExamples
-  I've slept in my undershorts, but I was too tired to change out of my shirt last night.
 -  Wandering the streets wearing only his undershorts and trying to find help, he is spotted by two young women who try to help him.