An adjective for the noun quiver could be violent--a violent quiver.
The word quivering (present participle of to quiver) *can be* an adjective (quivering assistants, quivering pets). It can also be a verb form or a noun (gerund).
(For archery, the other requisite, though not the opposite, is the "bow.")There is no word that means "not to quiver" (i.e. remain steadfast and unafraid). However, the adjective quiveringhas the opposites unafraid, unflinching, and undaunted.
quiver
The word quiver is the collective noun for a quiver of arrows.
Quiver
The collective nouns for arrows a 'sheaf of arrows' or a 'quiver of arrows'.
quiver (case for holding arrows)
A group of cobras is called a quiver
The arrows were stored in a quiver.
a smack of jellyfish a quiver of cobra
A quiver if you have them for use, but not drawn. A rest if it is used to hold the arrow in place during the draw.
Robin Hood had many arrows in his quiver.