A geomantic figure is four rows of one or two points and nothing else. The reading, the planet and the sign are all later additions to that skeleton.
The pattern
Amissio is single, double, single, double, reading Fire, Air, Water and Earth from the top down, six points in all. Its rows alternate light and heavy in strict turn, a property it shares with only one other figure in the sixteen.
Flipping every row
Change each row from single to double and from double to single and Amissio becomes Acquisitio. The two alternating figures are each other's partners, so loss and gain sit opposite one another in the structure as well as in the Latin.
What the name carries
Amissio means loss, and the handbooks read it as something leaving the querent's hands: a thing given up, spent, or simply gone. Several of the Latin authors add that the figure is not automatically unfavourable, since a question about escaping something reverses which outcome the querent wants. That caution is worth keeping, because the figure names a direction of movement rather than a verdict.
The attributions
The planet, sign and element recorded for this figure elsewhere in the atlas come from the astrological layer that later authors laid over the sixteen, not from the points. Agrippa, Cattan and the English handbooks differ on several assignments, so those columns record a tradition. The point pattern is the part that can be checked by counting.