This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A wave phenomenon sharing the physical nature of sound but with a range of frequencies below that of human hearing.

n. Sound waves having frequency below the human audible range (below about 20 Hz).

"And I recall from my army papers, that internal organs have their resonating frequencies, but they are generally in infrasound range."

ultrasound   

infrasonic    infrasonics   

static-discharge    nondimensional    10-khz    non-starfleet    repeti