This character is a fusion of two characters which were separate in small seal script.
甾 of this sense was 𠙾-like in the small seal script, with three vertical straight strokes on top, representing the pictogram (象形) of a bambooware. This became the current form in the clericalscript.
This glyph was used as 載 (OC *zlɯːs) or proper nouns in oracle bone script.
The glyph of this sense is composed of 𡿧 (“calamity”) and 田 (OC *l'iːŋ, “field”). This glyph is also used as an alternative form of 災 (OC *ʔslɯː).
This character was practically obsolete before it was revived as a modern translation for steroid. It is also a pictogram (象形) in this sense; the upper part represents the three side chains on the ring system, and the 田 component represents the tetracyclic core of steroids. See the image on right.