Marshall Eriksen (Jason Segel) is Ted's college roommate and now best friend in How I Met Your Mother. Marshall is engaged to and eventually marries his college sweetheart, Lily.
Marshall is a lawyer who always wanted to work as an evironmental lawyer but in an effort to provide for his wife and future family now works with Barney at a big bank corporation.
Marshall was previously Ted's roommate for the first few seasons but now lives with Lily in their own condo they purchased.
Barney: Barney Stinson is back on the market. Mothers, lock up your daughters. Daughters, lock up your MILSWANCA's.
Ted: Oh wait, I can get this. Mothers I'd Like to Sleep With and Never Call Again
Barney: Correct, circle gets a square
Lily [on the phone]: Hey, baby. It's lunchtime, and I love you.
Marshall [on phone in front of co-workers]: I reciprocate in principle, although with the caveat that there seems to be a bit of a surplus here on my end.
Lily: No, I love you more.
Marshall: Do we need to get in a room together and bang this thing out? (pause) Those sound like agreeable terms, although I may need to adjust my briefs