| 释义 |
Definition of alidade in English: alidadenoun ˈalɪdeɪdˈaləˌdād A sighting device or pointer for determining directions or measuring angles, used in surveying and (formerly) astronomy. Example sentencesExamples - A wide variety of alidades and plane tables are available, both in manual and electronic versions.
- In the circle an index on the alidades gives the angle that they form with the vertical diameter.
- A pointer, called an alidade, was pivoted at the centre of the disk.
- Both the alidades and the straight edges of the quadrant are fitted with viewers.
- Telescopic alidades came into use in Europe in the early 1800s, and were soon introduced to American practice.
Origin Late Middle English: directly or (in modern use) via French and Spanish from Arabic al-‘iḍāda 'the revolving radius', probably based on aḍud 'upper arm'. Definition of alidade in US English: alidadenounˈaləˌdād A sighting device or pointer for determining directions or measuring angles, used in surveying and (formerly) astronomy. Example sentencesExamples - In the circle an index on the alidades gives the angle that they form with the vertical diameter.
- A wide variety of alidades and plane tables are available, both in manual and electronic versions.
- Both the alidades and the straight edges of the quadrant are fitted with viewers.
- A pointer, called an alidade, was pivoted at the centre of the disk.
- Telescopic alidades came into use in Europe in the early 1800s, and were soon introduced to American practice.
Origin Late Middle English: directly or (in modern use) via French and Spanish from Arabic al-‘iḍāda ‘the revolving radius’, probably based on aḍud ‘upper arm’. |