The 7th house corresponds to an air sign and is therefore a house of kama (desire).
The 7th house is relatively simple in that it is essentially the house of marriage and partnerships in general. It reveals the quality of married life, as well as the condition of the spouse. It also governs residence in foreign countries.
The 7th house, being a kendra (angular house). Is considered generally fortunate, and the ruler is therefore an asset to the house it occupies.
The karaka, or indicator, of the 7th house is Venus.
Retrograde lord of the 7th house — the person will not have much desire to marry, or there will be difficulties or delays in registering the marriage. With a spouse, as a rule, a connection with a past life.
Source: «Ancient Hindu Astrology for the Modern Western Astrologer» by James Braha