四

square; formal; prim; stuffy

periphery; circumference

quarter (of a year)

age forty; one's forties

Sichuan (China); Szechuan; Szechwan

four-character compound word (usu. idiomatic)

the four classical chemical elements (fire, earth, air and water)

Baseball

base on balls; walk; pass

four-wheel-drive car; 4WD car

to be square; to be angular

to be formal; to be stiff; to be strict

four arithmetic operations; basic arithmetic operations

Sumo

the 48 basic techniques

every trick in the book

Colloquial

the 48 basic sexual positions

the four gentlemen (plum, chrysanthemum, orchid, and bamboo)

crawling on all fours; being on all fours; being on one's hands and knees

the four most important tournaments in a particular sport; grand slam tournaments; majors

Buddhism

the four kinds of demons that make trouble for sentient beings

From the anime/manga Doraemon

4D pocket; magical pocket that can hold any item

quadrangular prism

Organization name

Yotsuyakaidan

sihu (4-stringed Chinese musical instrument played with a bow)

torn asunder; disrupted and disorganized

Common noun; Buddhism

four essential elements of existence (birth, ageing, illness and death)

Noun or verb acting prenominally; Mathematics

four-phase; quadri-phase

quadruplets

Sichuan (China); Szechuan; Szechwan