What is another word for cross-fertilisation?

It depends which cross-fertilisation you mean. In the sense “fertilization by the union of male and female gametes from different individual of the same species”, the synonyms are cross-fertilization. Across all 2 senses there are 1 distinct synonyms, and they are not interchangeable with each other — this page lists them under the sense each one belongs to.

What is the opposite of cross-fertilisation?

WordNet records no antonym for cross-fertilisation. Antonymy in WordNet is a relation between specific word forms rather than between concepts, so it is recorded only where lexicographers judged the pairing direct. An absence here means none was recorded, not that none can be imagined.

Why are the synonyms for cross-fertilisation split into groups?

Because cross-fertilisation carries 2 recorded senses and each has its own set of substitutes. A single flat list would put words from unrelated meanings side by side with nothing to tell them apart, which is exactly how a writer picks the wrong one. The grouping comes from WordNet's synsets, not from an editorial judgement of ours.

Where do the synonyms for cross-fertilisation come from?

From Princeton University's WordNet, a lexical database maintained by lexicographers since 1985. A synonym here means a word form that shares a synset with this word — a set of forms interchangeable in one recorded context. Nothing on this page is generated by a language model.

Synonyms and antonyms

cross-fertilisation

nounRare

cross-fertilisation has 1 distinct synonym spread across 2 of its 2 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.

1
Distinct synonym: 0
Antonyms: 2 of 2
Senses with a relation

Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.