初

meeting for the first time; first meeting

first (written) contribution; first post (on a blog, social media, etc.)

first proof; first-proof sheets

Sumo

first tournament for a wrestler

firstborn; first-produced; newborn

Noun or verb acting prenominally

first-time; initial

しょげつ／はつづき only

first month of the lunar calendar

しょげつ only

first month

first moon of the month; new moon

Physiology

menarche; first menstruation

first print (run)

はつずり only

first print of the new year (esp. newspaper printed on January 1)

first trial

first laugh of the year

first five syllables (of a tanka); first line (of a poem)

first publication

initial response

baby's first annual festival

first sound of cicadas of the year

Computing

initializer

for the first time

volume one; first volume

first wholesale produce market of the year (usu. auction of seafood, fruit, etc.)

first cargo of the year

Archaic; Noun or participle which takes the aux. verb suru

crowning a boy for the first time at a coming-of-age ceremony

ういかんむり only

noh cap with a rolled or drooping tail (indicative of nobility)

first chrysanthemum of the year

Shinto

ceremony fee; money dedicated to the gods when participating in a ceremony