English Reference
noun

dissertation

n.
US /ˌdɪsɝˈteɪʃən/ UK /dɪsətˈeɪʃən/ dis·ser·ta·tion UK spelling dissertation's, dissertation's

  1. 01 C2 Proficiency FormalLiterary

    a long, serious speech or piece of writing about a subject.

    a lengthy and systematic discourse or treatise on a particular topic, not necessarily for academic credit.

    Simple

    He gave us a long dissertation on why the old laws were better.

    In context

    The professor launched into a spontaneous dissertation on the evolution of gothic architecture, ignoring the original topic of the seminar.

This article is adapted from her in-progress doctoral dissertation.

The Conversation· 14 Aug 2026

His dissertation examines what reading specialists understand about K–3 Spanish-speaking students' home language and literacy skills and how they can leverage them to build English proficiency.

Phys.org· 13 Aug 2026

From Latin dissertātiō, from dissertō.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin dissertātiō
Level C1 · Advanced
Frequency Frequent
Updated