register-specific word; sociolectal word
Linguistics term for a word whose usage is restricted to a particular social group, situation, or register (e.g., slang, jargon, honorifics, gendered speech).
"位相語" is a linguistics term that refers to words used in specific groups or situations.
Youth slang and technical jargon are considered types of register-specific words.
レジスター (register) is a broader concept in linguistics covering situational language variation; 位相語 specifically denotes lexical items characteristic of a register.
Compound of 位相 (phase, aspect) and 語 (word). The exact derivation is uncertain; the term is used in Japanese linguistics to describe words that vary according to social or situational factors.