A「person among wetlands」suggests being down in a VALLEY somewhere, since not too many marshes are found on mountain slopes for some reason…significantly,「wetlands」(o-manko in Japanese) is the Asian euphemism for a female's crotch.
　As seen in some uses of this glyph as an element (for example 卻 and 郤), formerly「two people in pile, meat pile」on an「orifice」that would likely result in V-SHAPES (apex up, apex down) being formed by their two sets of legs, an open space「^」(not, for example, a wedge). In most fonts today,「emissions with person and orifice」depicts a「person with opened legs」in an inverted V-SHAPE, literally perhaps a male or female standing and urinating, VALLEY-SHAPED (see 'splashing down' 浴), with the orifice being the urethral opening in either case. For hundreds of thousands of years, human beings all squatted while defecating, and females while urinating also—nobody sat down on a throne to do so until there was royalty. But males for millennia have stood while urinating, forming an inverted V-shape with the legs. Note that in English, the word VALLEY means 'lifted, raised on each side' as are both a vulva and buttocks, parts equipped with an「orifice of a person with emissions」and not formerly designating a condition of being in the groove as it were.
　Also represents a FORM THAT CONTAINS SOMETHING. In many cases, valleys are formed by meltwater or rainwater runoff over a long, long time, and each rainfall is CONTAINED within the valley…there may not be a running stream on the valley floor every day, but when it rains there is runoff water, either above or below the ground surface.
　For some obvious reasons, simplified Chinese uses this glyph to replace 'male often flinging sticky wads at tip of woody upwards from stretched skin of crotch and so on' (穀), and to mean GRAIN, CORN, MILLET (芑) that is also used as a reference to drops of gleet, TO BE IN A DILEMMA, to find oneself IN A BOXED CANYON, NO WAY OUT, AT THE END. Grain and millet are used extensively in the glyphs as euphemisms of encrusted gleet and gonorrheal-related dripping from the tip of one's stalk or stem. CORN is a fast-growing grass with long green stems and dull yellowish seed cobs which appear to be spewing constantly at the tip when ripe (「cornsilk fibers」), the same as various colors of gleet discharges.

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: grain; corn; valley
Japanese: valley, ravine, chasm, dell, cleavage, to terminate, to reach an extreme, to take to the extreme, to be in a dilemma, to be at an end
Unihan extended: valley, gorge, ravine
EDRDG: valley

Used within names (nanori)
がい　･　がえ　･　がや　･　せ　･　たり　･　たん　･　や