Aphabetic letter pairs in words

FE: fee

FF: Laffer (as in Laffer curve)

Bluff would have avoided a proper noun.

FG = afghan (the blanket, not the nationality)

[DEL]FG: offgassing[/DEL]

FH: cliffhanger

FI: affiliate

FJ: fjord

FK: elfkin

FL = ROFL

Just kidding. Fluoridation.

FM = halfmast

FN - Deafness

FO - exfoliate

FP - scarfpin

FQ = Elfquest

FR - Africa

FS - scarfs

FT = left

FU - defunct

FV - OffVis

(Microsofts Office Visualization Tool, used in combating MS Office software-based system breaches, viruses, etc.)

FW - beefwood