pizza, fuzzy
Some words start with Z and have double S: zaniness. zestfulness. zealousness. zipless. zoneless. zestless.
Zigzag, buzzword, jazzed.
z is not a vowel
Rendezvous
pizazz
Yes
There are not any letters z in this sentence, but there are two places where you pronounce /z/: words and friends. You pronounce them as /z/ because d is a voiced sound.
Zinc.
Yes
Words with double t's:atticattachattainattireattitudebatterybettingbrittlebarrettebuttressbetterbitterbottlebutterbuttonblottercattlecassettecommitteecluttercottoncuttingdittodiskettedinetteetiquetteflutterfritterfatterfetteredfittedglittergutterhitterhotterjitterykettleknittedknottedlittlelotterylettermattermattednettedotterpatternpattypattedpottingpotteryputterpettedrattlesettlestutterspattersputterspittingsplittingspottedswattedslottedscattertattleutterlyvettedwittedkittenlitterbatteredpatternsbetterbottompermitted
zero z-coordinate on a z-axis, zilch, zombie (math student)