Dictionary term
Alidade
Direct answer
Alidade is a rotating sighting rule or telescope used to define a direction on a graduated instrument.
Alidade is a sighting rule used in historical astronomy, timekeeping, or navigation.
- Source
- The Great Almanac Dictionary
- Category
- Historical Almanacs & Instruments
- Also appears in
- Historical Almanacs & Instruments
- Aliases
- None listed
- Last updated
- 2026-07-16
Quick reference
- Use when
- Use Alidade by aligning both sights with the target while keeping the supporting plane properly oriented.
- Do not use it for
- A bent sight, parallax, poor leveling, or a shifted pivot introduces systematic error.
- Reference category
- Historical Almanacs & Instruments
- Related terms
- Sector Instrument, Dioptra, Plumb Line, Gnomon
The story behind Alidade
Alidades appear on astrolabes, plane tables, quadrants, surveying instruments, and later telescopic circles.
Alidade in spiritual tradition
Alidade rewards careful observation, explicit assumptions, and humility about the limits of every model or measurement.
The Great Almanac frames Alidade with educational restraint. Mystical or symbolic language may be meaningful, but it should not be exaggerated into certainty, panic, or permission to ignore ordinary responsibility.
Alidade in the Bible
This is a factual history-of-science, instrument, timekeeping, or navigation reference. It may support wonder and disciplined attention without becoming a claim of fate, worship, or private revelation.
Alidade in numerology
Alidade is not a numerology claim. Any numbers attached to it should retain their ordinary scientific, calendrical, navigational, or historical meaning unless a separate symbolic interpretation is clearly labeled.
Why Alidade matters
Alidade matters because it converts a line of sight into a readable angle or plotted bearing.
Example in a reading: On an astrolabe, the alidade can sight a star while its pointer marks altitude on the limb.
Interpretive caution: A bent sight, parallax, poor leveling, or a shifted pivot introduces systematic error.
How Alidade is used in a reading
Use Alidade by aligning both sights with the target while keeping the supporting plane properly oriented.
Where interpretation stops
Alidade is presented as sourced astronomy, calendrical, Earth-science, cultural, or instrument-history reference. Definitions should distinguish measured phenomena from civil convention and historical interpretation, preserve location and time dependencies, and avoid turning factual sky data into a deterministic personal claim.
Sources and editorial method
Research references used for this entry include:
- Royal Museums Greenwich: Astronomical and Navigational Instruments - Museum reference collection for historical observing, calculating, timekeeping, and navigation instruments.
The page starts with a direct definition, then separates use, example, caution, spiritual meaning, and historical context. For astrology, occult, demonology, curse, and spiritual warfare terms, the editorial rule is to explain the term without making fear-based, fatalistic, medical, legal, financial, or ritual-instruction claims.
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These related entries help place Alidade inside a wider reference cluster instead of leaving it as a standalone keyword.
