Is the character 跌 (to trip) a deliberate combination of 足 (foot) and 失 (to lose)? The character


跌 (diē) = "to trip", etc.


is composed of two parts


on the left there is 足 (zú) = "foot", and
on the right there is 失 (shī) = "to lose", etc.


And indeed 失足 means "to lose one's footing".  It feels like the components of 跌 are not just a coincidence.  However, Chinese hanzi tend to have long histories so it can be hard to tell.

Question: Is the character 跌 (to trip) a deliberate combination of 足 (foot) and 失 (to lose)?
Yes, it is a deliberate combination. But 「失」 is also a sound hint!
「跌」 (Baxter-Sagart OC: /*lˤi[t]/, to fall, stumble) is comprised of semantic 「足」 (foot) and simultaneously semantic and phonetic 「失」 (/*l̥i[t]/, to lose).

Compare several other characters in the phonetic series: