Investigating the Laws of Synonymy Evolution through a Fine-Grained Lemma-Based Framework

Eduardo Calò, Pierluigi Cassotti, Stefano De Pascale, Nina Tahmasebi, Pablo Mosteiro


Abstract
We investigate how synonyms evolve over time, focusing on two apparently contradictory tendencies: the Law of Differentiation, whereby synonyms diverge in meaning, and the Law of Parallel Change, whereby they co-evolve. We develop a framework that breaks down the laws into a fine-grained taxonomy, which we use to construct a diachronic dataset based on the Oxford English Dictionary. We rely on definition embeddings and the use of LLM-as-a-Judge to link synonyms. We validate our methodology by performing a human evaluation on a subset of the constructed dataset. Finally, we populate the taxonomy and conduct extensive analyses across different time spans to investigate the predominance of each law in English over time. We find that while the Law of Differentiation is larger in absolute numbers, it is driven by the general tendency for meanings to disappear from the language rather than by a property unique to synonymy.
Anthology ID:
2026.emnlp-main.2021
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
46036–46052
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2021/
DOI:
Bibkey:
Cite (ACL):
Eduardo Calò, Pierluigi Cassotti, Stefano De Pascale, Nina Tahmasebi, and Pablo Mosteiro. 2026. Investigating the Laws of Synonymy Evolution through a Fine-Grained Lemma-Based Framework. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 46036–46052, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Investigating the Laws of Synonymy Evolution through a Fine-Grained Lemma-Based Framework (Calò et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2021.pdf