labored
Requiring a lot of effort and looking or sounding strained.
Labored describes something that requires great effort and shows the strain of that work. When your breathing becomes labored after sprinting up three flights of stairs, you're gasping and struggling to catch your breath instead of breathing smoothly and easily. A labored explanation sounds forced and awkward, like when you're trying to describe a complicated video game to someone who's never played it and you keep stumbling over your words.
A writer might produce labored prose that feels stiff and unnatural, as if each sentence took tremendous effort to construct. An injured athlete might move with a labored gait, their limp showing how much pain they're pushing through.
Labored often suggests that something should be easier than it appears. Natural breathing shouldn't be labored. Good writing shouldn't feel labored. When something is labored, you can see or hear the struggle behind it, like watching someone try to open a jar that's stuck too tight. That visible strain is what makes it labored rather than simply difficult.