second base
noun [ C usually singular ] uk/ˌsek.ənd ˈbeɪs/ us/ˌsek.ənd ˈbeɪs/ (also informal second)
（棒球）二垒
the second place a baseball player has to touch in order to score, or a position near this place played by a member of the team on the field
Idiom
get to second baseidiom US informal触摸伴侣衣服下的身体，但没有发生性交
to touch a partner under his or her clothes, but not have sex