Yr rune

Yr, eur, iris, bow, rain-bow, yew-wood, yew-wood bow, error, anger, etc.

A sixteenth I speak to a coy maiden
to get me goodness and luck:
that changes and turns the wishes and mind
of the swan-white armed beauty.

The "yr-rune" is the inverted "man-rune", and as it designates the bow, so too does it present the waxing and waning moon in contrast to the full moon of the "man-rune", and so in the first instance it refers to the mutability of the moon, in the second instance as the "error-rune"-referring to the lunarlike mutability of the feminine essence, portrayed in later verses of the "Havamal" [Rules of Life] in the following way:

Do not trust the true words of a maid,
do not trust the woman`s true words,
her heart was shaped on a spinning wheel
the feminine heart is the home of fickleness.

The yr- or error-rune[Irr rune], which causes confusion, whether through the excitement of the passions in love, in play, in drink[ intoxication], or through pretexts of speech[ sophistry] or by whatever other means, will perhaps conquer resistance through confusion.
But the success of a victory gained by such means is just as illusory as the victory itself-for it brings anger, wild rage, and ultimately madness.
The "yr" or "error-rune" therefore also contrasts with the "os-rune", since it tries to force the conquest of an opponent with mere pretext instead of with real reasons. Therefore, it teaches: "Think about the end!"