Niggler [noun]

● Doubter

● Complainant

● Complainer

● Attacker

● Quibbler

● Caviler

● Censor

● Nitpicker

● Carper

● Backseat driver

● Criticizer

● Zapper

● Muckraker

● Defamer

● Disparager

● Scolder

● Maligner

● Slanderer

● Worrier

● Nagger

● Vilifier

● Faultfinder

● Aristarch

● Belittler

● Blamer

● Censurer

● Disapprover

● Disputer

● Fretter

● Hypercritic

● Mud-slinger

● Nit-picker

● Panner

● Reviler

● Sidewalk superintendent

● Niggler

● Gripe

● Nitpick

● Bickerer

● Quibblingly

● Nag

● Zoilism

● Puler

● Gripeful

● Quibble

● Cavilingly

● Gripingly

● Noyance

● Plaguer

● Tormina

● Incommodity

● Pesterment

● Annoyous

● Annoyance

● Troublesomeness

● Pesterer

● Nudzh

● Tweag

● Negative stimulus

● Twinge

● Peeve

● Grumble

● Importuner

● Abirritant

● Squabbler

● Cumbrance

● Pulingly

● Cavillation

● Irritatory

● Weak point

● Fuss

● Exulceration

● Dubitation

● Tormentry

● Qualmishness

● Grudger

● Whine

● Criticaster

● Padnag

● Abirritate

● Swivet

● Disquieter

● Argutation

● Remord

● Whinge

● Rouncy

● Cavil

● Anxietude

● Latrant

● Hem and haw

● Fribbler

● Miseased

● Fantod

● Ache

● Pesterous

● Moider

● Discomfort

● Inquiet

● Plaintful

● Querimonious

● Discommodate

● Worry

● Worrit

● Carriwitchet

● Unpleasant person

● Graphospasm

● Irritation

● Problem child

● Mogigraphia

● Counterirritate

● Inconvenience

● Fantigue

● Irk

● Kvetch

● Querimony

● Bickerment

● Snap at

● Dryasdust

● Shaffler

● Painable

● Minutia

● Critic

● Psittacism

● Piddler

● Mess around

● Plaguesome

● Disembarrassment

● Shrink back

● Singultus

● Essoiner

● Mammer

● Witzelsucht

● Vitilitigation

● Mess about

● Complainer