Antonyms for the phrase "portion out" include "combine," "accumulate," and "collect." The phrase "combine" implies putting together different things into one, instead of dividing them. "Accumulate" means to gather or amass gradually, rather than dividing into smaller parts. "Collect" also suggests gathering, but in a more general sense, without the idea of dividing or allocating. Other possible antonyms for "portion out" may include "assemble," "join," "unite," or "amalgamate." These words all suggest bringing things together, rather than breaking them apart. Overall, the antonyms for "portion out" all describe actions that involve combining, accumulating or gathering, rather than dividing or allocating.