sesqui-
/ˈseskwɪ/combining form
1- denoting one and a half表示“一个半”：
sesquicentenary.
1.1
- Chemistry (of a compound) in which a particular element or group is present in a ratio of 3:2 compared with another【化】表示（化合物）“两元素为三比二的”, “一倍半化合的”：
sesquioxide.
词源
from Latin semi- （see SEMI-）+que 'and'.