April
Tyrian light
Tyrian purple was the most expensive dye in the ancient world, made from sea snails. Dickinson uses it for the reddish-purple tones of early spring.
vermilion foot
The first red flowers of spring—likely hepatica or trillium, both early bloomers in Amherst. She's personifying spring as leaving footprints.
chanticleer
Medieval name for a rooster (from Chaucer's Canterbury Tales). His strut is more confident because breeding season starts in spring.
Nicodemus' mystery
John 3:1-21—Nicodemus asks Jesus how someone can be 'born again.' Jesus answers: 'The wind blows where it wishes...so is everyone who is born of the Spirit.' Spring is the annual answer to spiritual rebirth.