penumbra
n.
1660s, from Modern Latin penumbra "partial shadow outside the complete shadow of an eclipse," coined 1604 by Kepler from Latin pæne "almost" + umbra "shadow" (see umbrage). Related: Penumbral.
〔李〕[pen-;umbr;-an.] n. [物理]半影；（绘画）浓淡相交处 ←umbr (L umbra)=shade or shadow 阴影
〔李〕n.半影；阴暗交界处 [umbra=shadow] ←pen（e）-[GK] =almost几乎，近似
〔蒋〕[pen-半，umbr影] 半影，(日，月食的)半影