四

bluestripe snapper (Lutjanus kasmira); bluestripe seaperch

tetradynamous stamen

four-eyed fish (Anableps spp.)

Proverb

(the most thrilling relationships for a man are) another man's wife, a maidservant, a mistress, a prostitute, and finally his own wife

the four drug-control laws of Japan

tetrapod; quadruped

Tetrapoda

four-horned antelope (Tetracerus quadricornis); chousingha

titanium tetrachloride

four large domesticated fishes (black carp, grass carp, bighead carp, and silver carp)

Buddhism

Treatise on the Two Entrances and Four Practices

intermediate switch (UK); crossover switch (UK); four-way switch (US)

the four great Japanese grammar texts (Yamada, Matsushita, Hashimoto and Tokieda)

Proverb

harsh words make the going rough; consider your words; a round egg can be cut into a square

the Four Freedoms (as defined by Franklin D. Roosevelt: freedom of speech, freedom of worship, freedom from want, freedom from fear)

Slang; From 低姿勢、低依存、低リスク、低燃費

ideal husband who is not overbearing, is not dependent on his wife, has a stable job and does not spend a lot of money

Music

perfect fourth

registration black (in printing)

Martial arts

firstly vision, secondly footwork, thirdly courage, fourthly technique (the most important aspects of kendo)

fourth-class mail

Medicine

Category IV infectious disease

Mathematics

four-color problem; four-color map problem

(complaining about) this and that; one thing or another

without complaining (about this and that); without arguing; without grumbling; with good grace