IPA: /ˌɪntərˈspɪsɪfɪk/
KK: /ɪnˌtɜrspɪˈsɪfɪk/
Relating to or happening between different species.
The interspecific competition between the two plant species affected their growth rates.
Interspecific → It is formed from "inter-" (meaning between) and "specific" (from Latin "species", meaning kind or type). The word describes interactions or relationships that occur between different species.
Think of interactions that happen 'between' ('inter-') different 'kinds' ('species') of organisms.