two sets; two classes; double
Refers to two groups, pairs, or sets of things; can also mean 'double' in contexts like double suicide (心中). The gloss 'double' is less common as a standalone meaning.
I bought two packs of playing cards.
This school has two first-year classes.
Standard kanji spelling for 'two sets' or 'two classes'.
Numerical variant using Arabic numeral 2; common in informal or space-constrained contexts.
Compound of 二 (ふた, 'two') and 組 (くみ, 'set, group, class'). The reading ふたくみ is a regular combination of the native Japanese numerals and the noun.