Definition

Noun: 1. A unit of volume used in mining, equal to six cubic feet, for measuring bodies of ore. 2. A linear unit of measurement equal to six feet, used for measuring water depth.

Usage

The word "fthm" is a specialized term. Its primary use is in technical fields such as mining, marine navigation, and oceanography. It is not commonly used in everyday conversation.

Examples

• As a unit of volume (mining):
  • The survey estimated the ore body to be over five hundred fthm.
  • They extracted several fthm of coal from the new seam.
• As a unit of length (water depth):
  • The anchor line was let out for twenty fthm.
  • The sonar indicated a depth of thirty fthm at this location.

Advanced Usage

• The term is an abbreviation of the more common word fathom. "Fthm" is a standard written abbreviation used in technical notations, charts, and logs.
• In historical contexts, a fathom was originally a unit of length based on the span of a person's outstretched arms.

Variants and Related Words

• Fathom (n): The full, more common spelling of the unit of measurement.
• Fathom (v): To understand something deeply or profoundly after much thought.
  • Example: I cannot fathom why he made that decision.

Synonyms

• For the linear unit: six feet.
• For the volume unit: six cubic feet.

Notes on Meaning

The two meanings are distinct but related through the core measurement of six feet. The linear measurement (depth) is the original and more widely recognized meaning, especially in maritime contexts. The volumetric meaning is a direct derivation used specifically in the mining industry to simplify calculations of ore volume based on depth and area.

Noun

1. (mining) a unit of volume (equal to 6 cubic feet) used in measuring bodies of ore
2. a linear unit of measurement (equal to 6 feet) for water depth