オヤジ, Oyaji - Meaning in Japanese - 親父, 親仁, 親爺

The word oyaji means "father" in Japanese, making it synonymous with otousan, but sometimes it can refer to a man of certain age, similar to how the word ojisan works, or the owner of a shop instead

Kanji

The word oyaji written with kanji is oyaji 親父, and, though it already means "father," it's spelled with the kanji for "parent," oya 親, and "father," chichi 父, and, to make matters worse, if you spell it backwards, it's a kanji semordnilap, you see, you get the word chichioya 父親, which also means "father."

Note that oyaji 親父 is a jukujikun 熟字訓, that is, the father kanji isn't normally read ji 父, but in this word it is.

親仁, 親爺

In certain cases, the word may be written with different kanji instead of the kanji for father, as oyaji 親仁 or oyaji 親爺. This hints the word doesn't mean "father" in that instance, but refers to a random man or the owner of a shop instead.

オヤジ, おやじ

Sometimes the word is written without kanji, with katakana or hiragana instead.

oyaji オヤジ
oyaji おやじ

Usage

The word oyaji is mostly used by men. It's said to be a more informal word, colloquial, used in more casual contexts.

There are people who believe the word is rude and that you shouldn't use it if you respect your father, but they're few. In general, it's thought to be just a more relaxed, cozier word, not rude at all.

In anime, characters who use the word oyaji are often boys in a rebellious phase who keep rebelling against their fathers. That may lead you to think it's some sort of teen slang, slur or bad word, projected out of their mouths using angst as fuel for propulsion. This isn't true. The term oyaji is just a normal word.

Ofukuro

The word ofukuro お袋, meaning "mother," is similar to oyaji in that it's mostly used by men and that it's a colloquialism. Because they're similar like that, sometimes a character who uses one word uses the other one too.

Toward Older Men

Sometimes oyaji refers not to your own father but to some random man of certain age instead. This is also colloquial usage. Generally it refers to someone over their 30's or 40's, but sometimes the speaker is a child character who refers to a poor guy who's just in his 20's as oyaji.

Kitakita oyaji from the manga Mahoujin Guruguru 魔方陣グルグル

In this case, the word oyaji can be preceded by the demonstratives pronouns kono, sono, ano, or by adjectives. For example:

ano oyaji あのオヤジ
That old man.
kitakita odori no oyaji キタキタ踊りのおやじ
Old man of the north-north dance.

Toward Shop Owners

Sometimes the word oyaji can refer to the owner of a shop. This follows the exact same idea as oyaji referring to old men. So it works only so long as the owner of the shop is male. It's used, for example, toward the oyaji who runs a takoyaki stand, or a ramen stand, bar, etc.

Toward Bosses of Organizations

Also following the same principle, the word oyaji can be a casual way to refer to the boss of one's organization or group. In particular, you may see it used in anime by members of gangs, Yakuza, etc. to refer to their bosses.

Oyajisan

Like other words that refer to family members, it follows a certain norms on honorific usage. Specifically, oyajisan, with a san honorific, implicitly refers to other people's fathers, not yours. Except when you're talking to someone inside your family, then oyajisan may refer to your own father.