The top 田-shape is the indexing Kangxi radical. Originally 畏 depicted a ghost or spirit holding a weapon, with a head shaped like a fierce mask at the top; the masked head was reanalyzed as 田, placing 畏 in the field-radical family for lookup.
pictograph
畏wèi
fear; awe; revere
The lower strokes preserve the body of the ghost-holding-weapon original - a stylized clawed hand below the masked head. This menacing posture is the source of 畏's 'fear, dread, awe' meaning seen in 畏惧 and 敬畏.
