I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: shirt (I) + tail
1. : the part of a shirt that reaches below the waist especially in the back
2. : a short addition at the end of a newspaper article
II. adjective
1.
[so called from the stereotype picture of small boys with shirttails hanging out]
: very young
just a shirttail kid on the lookout for a horseback job — F.B.Gipson
2. : distantly and indefinitely related
he was a sort of shirttail relative but we weren't friends — G.C.Robinson
3. : marked by smallness or shortness
an airplane suitable for shirttail runs of 50 to 100 miles