I believe you're referring to the "Fight Defensively" option in 1.0 (take a -4 penalty to your attack bonuses to gain a +2 bonus to Armor Class for the round)? I haven't seen anything like that in 2.0 yet.
EDIT: I just did a Rulebook-wide search using the word "Defense." Fighting Defensively appears to be in 1.0 only.
EDIT: I just did a Rulebook-wide search using the word "Defense." Fighting Defensively appears to be in 1.0 only.