1Two people; a pair or couple. Usually read 'ふたり' in everyday speech; the reading 'ににん' is more formal and appears mainly in set compounds.
駅前で友達と二人で待ち合わせをした。
I met up with a friend, just the two of us, in front of the station.
このレストランは二人用の席が多い。
This restaurant has many tables for two people.
彼らは大学時代からの二人だけの友情を今も続けている。
The two of them have kept up their friendship, just the pair of them, since university.
子供が二人いるので、車は大きい方が便利だ。
Since I have two children, a bigger car is more convenient.