「Vertical motion, rod」within「cavity」: ask any pre-kindergartener to draw a mountain, and virtually no one will draw this specific shape. Scholars claim 'every viewer will mentally connect the peaks' as is often taught (…is that true, though?..did you, the first time seeing this glyph?). Elements depict either something EMERGING from a cavity or a surrounding sheath, such as a new plant sprout (see 屮), or in a series of「vertical motions」that have PEAKED, or formed a peak from spatter and flows, as does molten lava spurted multiple times from within a volcano, the single most prevalent method by which a single MOUNTAIN forms such as the Hawai'ian Islands, Mount Fuji, and Mount St. Helens as nonly a few examples among many. The lava flow path is called a lava channel or lava tube, the conduit through which molten rock is confined within a tunnel-like structure, the「sheath, cavity」from which hot spurting occurs through channelways that lead from the magma reservoir to the vent. Starting to resemble the prostate-to-meatus channelway of male anatomy yet? Were the sages depicting analogous systems or structures? No one can prove otherwise. Note that lava is sticky, and volcanic pyroclastic flows are stinky (toxic, too) a A PLACE FOR PRODUCING STICKY STINKY THREADS.
　Chinese sources continue the analogy in another manner, listing the meaning as A PLACE FOR PRODUCING STICKY STINKY THREADS: given meaning in Chinese as a wad or bundle of sticky threads spurted by the head of worm-like shapes (with the extended meaning of silk caterpillars: see 糸 for details), a reference further associating this glyph with the glans penis and the source of「ejaculated threads」wound into a ball, perhaps within poultice netting worn within a loincloth…see 綃, 素, and 生. Not coincidentally, 疝 as a sick whatever-this-is means 'inguinal hernia, ruptured meat emerging' and mountains do not contract illnesses, ever.
　While it is often true that a single MOUNTAIN「emerges with peak,」mountains are clearly not the only thing that emerges or is peaked, so it is best not to limit the meaning in this manner. A mountain forms as the result of volcanic activity in which molten LAVA EMERGES from deep within the hollow shaft of a cavity, erupting in a sticky flow until hardening and forming a crust that is often PEAKED, sometimes exploding and blasting poisonous gases especially during the initial moments. Similarities to a GLANS that emerges and gushes hot, sticky, thick liquid and stinks are not only obvious, but the only way to explain the use of this element in many glyphs that have no apparent connection to geology. Continuous mountain ranges such as the Andes, Rockies and Himalayas are formed from a different geological force and not eruptions, that of the plates of the Earth's crust moving over one another, or colliding very slowly.
　Reference to the flowering shrub Helicia cochinchinensis seems to relate the shape, sticky texture, and color of the plant's flowers to a glans during ejaculation, readily apparent if one views images of these flowers.

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: mountain; hill; anything that resembles a mountain; bundled straw in which silkworms spin cocoons; gable
Japanese: mountain, hill, mine, heap, pile, crown, thread, climax, peak, critical point, guess, speculation, to pile up, to form into a pile, a heap, great amount of, plentiful, lot of, Helicia cochinchinensis
Unihan extended: mountain, hill, peak
EDRDG: mountain

Used within names (nanori)
さ　･　やの　･　やん