keenkinkingpin
Some words beginning with P and ending with K:PackPaddockPadlockPaintworkPaperbackPaperworkParkPartookPassbookPassmarkPatchworkPaybackPaycheckPeacockPeakPebrookPeckPeekPerkPickPickabackPickwickPieceworkPiggybackPillockPinkPinprickPipeworkPipsqueakPitchforkPlacekickPlanckPlankPlasterworkPlaybackPlaybookPlonkPluckPlunkPockPocketbookPockmarkPollackPollockPoppycockPorkPostmarkPothookPotluckPrankPreshrankPreshrinkPreshrunkPresoakPrickPuckPullbackPunk
killer, kilter, kisser
Some words beginning with P and ending with K:PackPaddockPadlockPaintworkPaperbackPaperworkParkPartookPassbookPassmarkPatchworkPaybackPaycheckPeacockPeakPebrookPeckPeekPerkPickPickabackPickwickPieceworkPiggybackPillockPinkPinprickPipeworkPipsqueakPitchforkPlacekickPlanckPlankPlasterworkPlaybackPlaybookPlonkPluckPlunkPockPocketbookPockmarkPollackPollockPoppycockPorkPostmarkPothookPotluckPrankPreshrankPreshrinkPreshrunkPresoakPrickPuckPullbackPunk
Kilmarnock
Fork.
Some six letter words ending in K are:attackdamaskembarkhijackremarkshriekshrink
Some five letter words ending in k include:slackstackstinkstunktrucktrunk
Not in any dictionary I tried (two of which contain over 250,000 words each).
Turtleneck...
kayak, kiosk, knack, knock, kapok Special bonus: klunk
knack, knock, kayak, kapok, kiosk Special bonus: klunk