Legging – partially enter or exit a complex option spread by adding or exiting option legs one by one.
This doesn’t enter the intended trade as a package (eg 4 option legs for an iron condor). This definitely incurs more commissions, but can get executed at better prices IF you can judge market direction while entering on option leg (eg sell call spread into an up move and sell out spread into a down move, to create a better price for an iron condor). In the long run legging can get better prices if you are particularly talented at predicting the underlying direction (which we ARE NOT so generally we don’t bother with legging). See also leg out definition.