Use 'peerless' to stress that someone or something is the absolute best and cannot be outdone. She has a peerless reputation in the field of neurosurgery.
Pro Tip 2/3
Positive Emphasis
'Peerless' is always positive and often used to praise highly exceptional qualities. The chef's peerless mastery of flavors won him numerous awards.
Pro Tip 3/3
No Competitors
Use 'peerless' when there are no competitors or rivals that come close in ability or quality. His peerless dedication to research sets him apart from his colleagues.