incidental russian

• наверну́вшийся

  fallen, stumbled

  that has appeared, that has turned up, incidental

  welled up (tears)

• приме́шивающийся

  admixing, intermixing, mixing in, getting mixed in, incidental, accompanying

• кста́ти

  by the way, incidentally, besides, in fact

  as a matter of fact, for the record, incidentally

  useful, helpful, handy, welcome, convenient

• попу́тно

  in passing incidentally at the same time

Examples

• Жабры рыб вы́глядят ярко кра́сными из-за большо́го скопле́ния капилля́ров, подо́бного тому, что есть в лёгких.

  Incidentally, that the gills of fish are bright red is because there are many 'capillary vessels' collected there, the same as for lungs.

• Кстати говоря, любопытно, из чего сделан э́тот знак. Лицевая сторона́ табли́чки я́вно довольно масси́вная, а насажена она на какую-то неро́вную доску́.

  Incidentally, I’m curious to know what that sign’s made out of. The “sign” part of the side is clearly quite thick, and the wood it’s attached to appears to be some manner of uneven plank.