Each string of letters can have a substring replaced with a synonym to form a new string, which can have a substring replaced with a synonym to form a word. In each pair of strings, the second word contains all of the letters of the first word but one.
F: LIDERATEDSFUSE --> TOPERATEDSFUSE --> TRANSFUSE COPYRCHRUS --> APERCHRUS --> ANESTRUS E: FOROFFERDENLATE --> FORBIDDENLATE --> TABULATE YESTTAL --> AYETTAL --> ABUTTAL L: TFONET --> TFACET --> TANGLE MATULEASE --> MATURENT --> AGENT L: TVIENT --> TCOMPETENT --> TABLE ASSEIZE --> ASTAKE --> ABET O: COLORELLECT --> TINTELLECT --> TREASON QUINGESTEDRN --> QUATERN --> ASTERN W: GREAPULL --> GREATOW --> TALLOW EVERYTHMOLD --> EVERYTHINGOT --> ALLOT E: TETHSTEALRS --> TETHROBRS --> TEACHERS SKILLRUNK --> ARTRUNK --> ARCHEST R: PRAISEBREAKIEST --> TOUTBREAKIEST --> TRASHIEST ATHFORMERUPS --> ATHOLDUPS --> ATHEISTS M: POINTLATEAUVERS --> TIPLATEAUVERS --> TIMESAVERS DONKWATCHRTIVE --> DONKEYERTIVE --> ASSERTIVE I: TSHOWECRIMSON --> TSHOWERED --> TRAINED AEDGEPRESSION --> ARIMPRESSION --> ARDENT T: TCHARGEBLES --> TFEEBLES --> TWEAKS QUESTIOFRESH --> QUESTIONEW --> ASKEW
The letters that appear in the first words but not the second are FELLOWERMIT, which by the same process becomes CHAPERMIT and finally the answer, which is CHALET.
Also, each pair of words begins with the same letters, which are the hidden bigram TA.