his gesture is some where between surrender and ____________.

supplication, riveting, or arduous

supplication

The missing word to complete the sentence is "supplication."

To determine the missing word in the phrase "his gesture is somewhere between surrender and ____________," we can analyze the provided options: supplication, riveting, or arduous.

To begin, let's understand the meanings of each option:

1. Supplication: Supplication refers to a humble or earnest plea or request, often made to a higher authority or power.

2. Riveting: Riveting means holding one's attention completely or being intensely fascinating or absorbing.

3. Arduous: Arduous describes something that requires great effort, difficulty, or strenuousness.

Considering the context of the phrase, we are looking for a word that describes a gesture that is similar to surrender but not exactly the same. Surrender implies giving up or conceding, so we need a word that expresses a similar idea when combined with the concept of a gesture.

Given this information, the most suitable option from the provided choices is "supplication." A gesture that is somewhere between surrender and supplication indicates a movement or action that shows both a sense of giving up or yielding, like surrender, and a humble plea or request, like supplication.

In summary, the missing word in the phrase is "supplication."