Sandhi

Sandhi

"connection", "junction", "transition point", "place of contact" 

In a general sense, "sandhi" means the area of mutual action, transition, borderline influence, it can be:

• a euphonious fusion of sounds (letters) when connecting words or parts of a complex word;
• dawn, dusk, as a connection of light and darkness;
• the horizon is like the boundary between heaven and earth;
• an agreement or contract between two or more parties, especially concerning the resumption of an interrupted relationship — reunification, reconciliation;
• seam, joint, spike, that is, what connects the parts into a whole;
• transitional time between epochs (yuga-sandhi), etc.

Sandhi in Sanskrit Grammar

There is a whole section in Sanskrit grammar devoted to sandhi, or the laws of euphony. 

In Sanskrit, phonetic writing is accepted, that is, it is heard and written the same way. When speaking freely, the sounds of some neighboring words or sounds inside a complex word often merge. Such changes in spoken sounds are reflected in the spelling of words and are called "sandhi". There are internal and external sandhis. Internal sandhis act at the junction of morphemes within the word, as well as in the absolute outcome. External sandhis act at the junction of words in phrases and between the members of a compound word.