Consolidation [of Knowledge]: You must acquire 100 hours of line operating time within 120 days of your checkride. For SIC's, IOE counts towards the 100 hours. For PIC, the 100 hours must be as actual PIC (after IOE). Completion of consolidation marks the completion of your initial training on a new aircraft.

Probation specific to each major: Varies by company. Typically one year, either calendar to the day, or upon completion of annual recurrent checkride. You have few union protections on probation, and do not pay union dues.

Displaced. Removed from a trip because the seat is needed for training another pilot (IOE). You should get paid, but may or may not be assigned something else. Also kicked out of your position in the event of downsizing.

IOE. Initial Operating Experience. Your first 40+ hours (depending on aircraft type) on line, which is flown with a check airman. This is training, can be failed, and finishes with a line check.