Particle
Usually written in kana
1. while; during; as
after the -masu stem of a verb
語りながら、彼の声に込められた力が強くなっていく。As he speaks, the power imbued in his voice grows stronger.
2. while; although; though; despite; in spite of; notwithstanding
彼は知っていながら、何も言わなかった。Even though he knew, he didn't say anything.
3. all; both
4. as (e.g. "as always", "as long ago"); in (e.g. "in tears")
5. while doing something else (at the same time)