Somewhat like glue; having qualities of glue but not completely or perfectly gluey; partially sticky or adhesive.
From 'glue' plus the diminishing suffix '-ish,' which softens the meaning of an adjective (compare 'reddish' to 'red' or 'coldish' to 'cold').
The suffix '-ish' is incredibly useful for expressing uncertainty or partial qualities—'gluish' means 'kind of like glue but not exactly,' which is why English speakers use it constantly in everyday speech even though style guides sometimes warn against it.
Complete word intelligence in one call. Free tier — 50 lookups/day.