In summary, what is often described as "loss aversion" is actually just an expected property of diminishing marginal utility, and does not require a new term to explain it.

Loss aversion, instead, is state dependence that makes you feel worse about state X if you came from state X+1, and better about it if you came from state X-1 (assuming X is, say, wealth).

It seems to me that "loss aversion" might be reconstituted as "utility hysteresis" to avoid the ambiguity.