Definition - What does Ahutis mean?
Ahutis are offerings made to deities during a ritual fire ceremony. Sanskrit for 'oblations,' ahutis are an important part of Agnihotra, Yajna and other Vedic rites, as described in ancient Vedic texts, such as Brahmanas.
It is common to chant mantras while offering ahutis to a consecrated fire, and 'Svaha' is usually chanted at the moment when the ahuti itself is offered.
Yogapedia explains Ahutis
The procedure of offering ahutis to the Gods begins by melting ajya (butter or ghee) over a sacred fire. It is then purified by dipping in darbha-grass, used specifically for oblations. After adding sacrificial fuel to the fire, a special offerings ladle, called a juhn, is then used to pour the ajya onto the fire, whilst uttering 'Svaha'. At the end of a rite, a larger quantity of ajya is offered, signifying the conclusion of ahutis. This is known as the purnahuti.