dels

English lexical lookup from a local datastore.

Given a word or expression, returns definitions, synonyms, and etymology.

Operates offline.

Data is sourced from Open English WordNet 2025, GCIDE 0.53, and Wiktionary via Kaikki.

dels lookup output

Requirements

• OCaml ≥ 5.3.0
• dune ≥ 3.23.1
• opam packages: sqlite3, yojson
• Python 3 (extraction pipeline only)
• Source datasets (see Building the datastore below)

Build

opam install sqlite3 yojson
dune build

Building the datastore

The datastore is not distributed. Please download the source datasets manually:

Place all three files in data/sources/, then run:

python3 data/extract_wordnet.py
python3 data/extract_gcide.py
python3 data/extract_kaikki.py
dune exec test/import_test.exe

The import takes several minutes. The resulting datastore is written to datastore/dels.db (~470 MB).

Install

cp _build/default/dels_cli/dels_cli.exe ~/bin/dels
cp datastore/dels.db ~/bin/dels.db

dels looks for dels.db in the same directory as the binary, so no configuration is needed when both files are co-located. Set DELS_DB to override the datastore path.

Usage

dels lookup run
dels lookup "out of hand"
dels lookup --json serendipity
printf '%s\n' run saw bank | dels

See dels(1) for full documentation.

man man/dels.1

License

ISC. See dels --license for data source attributions.

Sources