From Middle English unpakken, equivalent to un- + pack.

• IPA: /ʌnˈpæk/

unpack (unpacks, present participle unpacking; simple past and past participle unpacked)

1. (transitive) To remove from a package or container, particularly with respect to items that had previously been arranged closely and securely in a pack.

   They didn't have time to unpack their bags before going out to dinner.

2. (intransitive) To empty containers that had been packed.

   They didn't have time to unpack before going to dinner.

3. (figurative, transitive) To analyze a concept or a text; to explain.
4. (linguistics, intransitive, of a segment such as a vowel) To undergo separation of its features into distinct segments.
   • 2008, Katrin Dohlus, The Role of Phonology and Phonetics in Loanword Adaptation, page 73:

     Whereas the high vowels /ʏ, y/ unpack, the mid vowels /œ, ø/ are adapted as single segments in these languages (see examples in (36) for Vietnamese (Barker 1969) and (37) for Fon (Gbeto 2000)). […]
     French /y/ → Vietnamese /wi/
     accu [a'ky] → ac-quy [ak kwi]

   • 2011, John A. Goldsmith, Jason Riggle, Alan C. L. Yu, editors, The Handbook of Phonological Theory:

     The objective of these corpora was to check whether vowels other than nasal vowels systematically unpack in L1s that do not allow them.

5. (computing, transitive) To unzip, decompress.
   • 2005, Matthias Kalle Dalheimer, Matt Welsh, Running Linux:

     Packages […] are often archived and compressed using the zip utility; you can unpack these with the unzip command […]

• pack

• French: déballer
• German: entpacken, auspacken
• Italian: sballare, disimballare
• Portuguese: desempacotar
• Russian: распако́вывать
• Spanish: (Latin America) desempacar, (Spain, suitcase) deshacer, (Spain, package, box) desempaquetar