Some sources explain this element to mean 'stroke, stroking' and it very well may, but we should all realize that before these glyphs and elements were created, there was no writing or brush stroking; for at least a thousand years, glyphs and elements were scratched onto hard clay, scapula bones, and turtle shells using sharp implements, and not hand-crafted calligraphy brushes using goat or wolf hairs dipped into a mixture of soot and clay. So ask yourself: what was being stroked generally by bonobos and humans before the advent of written glyphs?
　Depicts ERECT, MOVES QUICKLY WITH AGILITY: some comments have denied or decried this element's meaning to be strange or doubtful, yet, considering the critical importance of erections for reproduction and the propagation of many animals, including virtually all mammalian species, it would be even more strange if such an essential concept for the continuation of human life were not included somewhere in these glyphs. It cannot be denied that all of us alive on the planet today owe our existence to the series of erections employed variously and successfully by our respective ancestors, and the same is true for all of the so-called 'higher' forms of life.
　Note that Chinese dictionaries refer this element to the glyph (撇)「use talented hands」with「sticky fluid emissions within spread legs」and「whacking」that means FLUNG (as in to cast away, to toss aside with a quick jerking motion...draw your own conclusions from that) while attempting to connect these elements to stroking, or, by diverting attention to calligraphy brush strokes…so which came first, the erection meaning or the stroking meaning? does it matter? paired with (乀) as 'stretched taut, on the other side too.'

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: radical in Chinese characters; see 撇
Unihan extended: line

Used within names (nanori)
の