significant other

US /sɪɡˈnɪf.ɪ.kənt ˈʌð.ər/
UK /sɪɡˈnɪf.ɪ.kənt ˈʌð.ər/
"significant other" picture
1.

companheiro, parceiro

a person with whom someone has a long-term, committed relationship, especially one who is not a spouse but is considered a partner in life

:
She introduced him to her significant other at the party.
Ela o apresentou ao seu companheiro na festa.
Many people prefer to use 'significant other' instead of 'boyfriend' or 'girlfriend' to be more inclusive.
Muitas pessoas preferem usar 'companheiro' em vez de 'namorado' ou 'namorada' para serem mais inclusivas.