l sill
B2Neutral; Technical (geology)
Definition
Meaning
The horizontal piece at the bottom of a window or door frame.
A base, foundation, or supporting structure; in geology, a flat, horizontal layer of igneous rock intruded between older layers of rock.
Linguistics
Semantic Notes
The core meaning is architectural/construction. The geological sense is a technical extension based on the shape and structural role.
Dialectal Variation
British vs American Usage
Differences
No major semantic difference. In British English, 'windowsill' (as a single word) is very common for the core meaning. In the US, both 'sill' and 'windowsill' are used.
Connotations
In both varieties, the core meaning is neutral and functional. The phrase 'sill plate' is common in US construction terminology for the bottom horizontal member of a wall frame.
Frequency
More frequent in the compound 'windowsill' than as a standalone noun in everyday contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
N of N (sill of the window)Adj N (stone sill)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “[No common idioms. The word is typically literal.]”
Usage
Context Usage
Business
Rare, except in property/construction contexts (e.g., 'check for damp on the sills').
Academic
Used in architecture, geology, and engineering disciplines with precise technical meanings.
Everyday
Common in home and garden contexts (e.g., 'plants on the windowsill').
Technical
Critical in construction (structural member) and geology (intrusive igneous rock formation).
Examples
By Part of Speech
verb
British English
- N/A
American English
- N/A
adverb
British English
- N/A
American English
- N/A
adjective
British English
- N/A
American English
- N/A
Examples
By CEFR Level
- The cat sat on the window sill.
- I put my keys on the sill by the door.
- She placed the flower pot carefully on the broad stone sill.
- Paint was peeling from the old wooden sill.
- The contractor confirmed the sill plate was treated against rot.
- Damp had risen from the foundation and affected the door sill.
- The geologist explained how the igneous sill had formed between the sedimentary strata.
- The architect specified a pre-cast concrete sill for the entire facade to ensure uniformity.
Learning
Memory Aids
Mnemonic
SILL is at the bottom, just like the word ends with two L's that look like a solid base.
Conceptual Metaphor
FOUNDATION IS A BASE/SUPPORT (The sill supports the window structure).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating as 'подоконник' (which is specifically 'windowsill') when referring to a door or geological sill. The broader Russian 'порог' can mean 'threshold' or 'sill', but for a door, not a window.
Common Mistakes
- Misspelling as 'sil'. Confusing 'sill' (bottom) with 'lintel' (top). Incorrectly using 'sill' for a shelf that is not part of a window/door frame.
Practice
Quiz
In which field would the term 'sill' refer to a layer of igneous rock?
FAQ
Frequently Asked Questions
No. While 'windowsill' is very common, 'sill' can refer to the base of a door frame (door sill) and has a specific, unrelated meaning in geology.
A sill is specifically part of a window or door structure. A ledge is any narrow, projecting shelf, often on a cliff or wall, not necessarily part of a frame.
No, 'sill' is exclusively a noun in modern English.
'Cill' is a rare, archaic variant, primarily found in very old texts. The standard modern spelling in both UK and US English is 'sill'.