Japanese meaning of ぼそぼそ

Meaning:

Describes speaking in a low, mumbling voice; also, something dry and crumbly.

Cultural Context:

Often used for awkward characters, or bad bread in manga.

小さな声でぼそぼそ話す、または食べ物がパサパサしている様子。
ぼそぼそ話す＝根暗キャラ。パンがぼそぼそ＝まずいパン。