This wasn't the kind of nicker you'd expect from a stallion either.
From the blogs.psychcentral.com
Reagan waited nearly four hours for a nicker of flexibility, any tiny gesture of accommodation.
From the time.com
Nicker beans, with sharp spines on their stems and seed pods and reverse barbs on their leaves, grow throughout the park.
From the heraldtribune.com
Until everyone got nicker-twisted about the Stig outing himself I'd always assumed he was just any good driver who was available on the day.
From the guardian.co.uk
Historically, the Bedouin nomads of the Arabian peninsula preferred mares on their raids, because stallions would nicker to the opposing camps'horses, whereas mares would be quiet.
From the en.wikipedia.org
More examples
Neigh: make a characteristic sound, of a horse
The neck, nicor, nixie or nokken (German: Nixe; Dutch: nikker, nekker; Norwegian: nu00F8kk; Swedish: nu00E4ck; Finnish: nu00E4kki; Estonian: nu00E4kk) are shapeshifting water spirits in Germanic mythology and folklore who usually appeared in forms of other creatures.
(nickers) noun, a pant-like garment that extends from the waist to the top of the knee.
Noun. One pound sterling. Also spelt 'knicker'. {Informal}
Nickname for a type of monster, usually encompasses those the size of a man or larger.