four / 4

= + : Mnemonic symbol: a four-leaved clover. Socrates (s) is working out in the bathroom of the space station (Ø4). He's lifting four (四) wooden boxes (囗), and wonders why they are so heavy. He doesn't know that inside one of the four boxes, the monkey king (儿) is hiding and secretly laughing at him - until the monkey king comes out and surprises Socrates with a four-leaved clover (四).

四 character breakdown

variant of 人[ren2] / "person" radical in Chinese characters (Kangxi radical 10), occurring in 兒, 兀, 兄 etc
child / son

= 丿 + : Mnemonic symbol: "son" (儿) sounds similar to "Sun" like in "Sun Wu Kong", so it's gonna be represented by the monkey king. Albert Einstein (Ø-) and Sun Wu Kong (儿) are fighting in the space station's kitchen (-Ø2). Their weapons: Albert Einstein has a shovel (乚), and Sun Wu Kong has a banana (丿).
non-syllabic diminutive suffix / retroflex final
enclosure

Mnemonic symbol: a plastic enclosure. Willy Walrus (w) is keeping frozen fish in an enclosure (囗) in the Eiffel Tower's kitchen (ei2).

Characters with 四 as component

river in Shandong
nasal mucus
team of 4 horses
to rest
spoon / ladle

Words with 四

dubious / shady / neither one thing nor the other / neither fish nor fowl / nondescript
seven heavenly bodies and four imaginary stars (in astrology and feng shui)
Confucian moral injunctions for women, namely: obey in turn three men father, husband and son, plus the four virtues of morality 德[de2], physical charm 容, propriety in speech 言 and efficiency in needlework 功

Sentences with 四