The spelling of the word "un pins" can be explained through IPA phonetic transcription. The first syllable "un" is pronounced as /ʌn/, which is the phonetic transcription of the sound "uh" followed by the sound "n". The second syllable "pins" is pronounced as /pɪnz/, which is the phonetic transcription of the sound "p" followed by the sound "ɪ" and then the sound "nz". Therefore, the correct way to spell "un pins" is as two separate words: "un pins".
The term "un pins" does not have its own unique etymology because it is simply a combination of two separate words: "un" and "pins". "Un" is a prefix derived from Old English, meaning "not" or "reverse", which is added to words to indicate negation or reversal. "Pins" is the plural form of the noun "pin", which can refer to a small, thin piece of metal or wood used for fastening objects. Therefore, "un pins" would suggest the action of removing or undoing pins.