What does sidelight mean?
A sidelight is, literally, a side window or light shining from the side. In older and more formal figurative use, it means an incidental fact, detail, or observation that provides limited additional information about a person, event, or subject. For example, a discussion of a politician's early career might be introduced as a sidelight on their later career. The word can also be used as a verb for light that falls on something obliquely or illuminates it from the side. Although it can sound literary or somewhat old-fashioned, the noun remains useful in architectural, artistic, and biographical contexts. Its figurative sense complements the literal one: just as light entering from a side can brighten a room without becoming its main source, a sidelight offers background knowledge that may clarify a subject without changing its central point.
A window in the side of a building; a light shining from the side; or an incidental detail or observation.
"A sidelight in the hall provided just enough light for the staircase."
The figurative senses are formal and comparatively uncommon in everyday speech.
To illuminate something indirectly or from the side.
"Late afternoon sun sidelighted the cliffs and turned the water silver."
This use is relatively uncommon and is chiefly found in descriptive or literary contexts.
The regular plural of the noun is "sidelights."
"Several narrow sidelights flank the entrance."
A sidelight can be both a window admitting oblique light and a lesser point that helps illuminate a subject from the side.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sidelight come from?
The word is a compound of "side" and "light," following the ordinary English pattern of compounds that specify a position or direction. It developed the literal meanings of a side window and light coming from the side before extending figuratively to incidental information. The component "side" comes through Old English and ultimately from an ancient Germanic root, while "light" comes through Old English from an inherited Germanic word meaning illumination or brightness.
Related word forms
How sidelight is actually used
The figurative sense is formal and often appears in the expression "by the sidelight" or "a sidelight on" something. The verb is less common than the noun and is especially associated with descriptive writing.
Easily confused with sidelight
A sidelight is a side window or an incidental detail, whereas a highlight is an especially important or notable feature.