Evolutionary term for multiple, related adaptations
Co-adaptation

The term you are looking for might be co-adaptation. Co-adaptation is kind of a generalist term that fits many scneario, its definition (source: wikipedia > co-adaptation)


  In biology, co-adaptation, or coadaptation is the process by which two or more species, traits, organs, or genes undergo adaptation as a pair or group. This occurs when two or more characteristics undergo natural selection together in response to the same selective pressure. While the parts may be functionally independent they are only beneficial when together, sometimes leading to increased interdependence. Coadaptation and its specific examples are often seen as evidence for the broader process of coevolution.


You seem to be thinking about a chain of adaptations, where the first adaptation changes the selection pressure on another trait causing another adaptation. For this purpose co-adaptation is not the perfect term but I am afraid there is no perfect terms. You might want to consider the following ones though that help you express your ideas.

Structural interdependence

Ziegler et al. 2009 talk about structural interdependence and interdependence of internal organ. 

Phenotypic space

Of course, you can use the frameworks of the phenotypic space (as in Pigliucci 2007) and of fitness landscape to talk about how a change in a given phenotypic trait affect selection pressures at other traits.

Phenotypic constraint

A phenotypic constraint (as in Pigliucci 2007) is a case of fitness valley in fitness landscape in the correlation between two of more phenotypic trait, hence causing a trade-off. Absence of such constraint are cases of interest to you

Phenotypic plasticity

It is common to talk about the ability of a specific phenotypic trait to vary to fit into the broader context of the whole body as phenotypic flexibility or phenotypic plasticity. There is a difference plasticity and flexibility for many but I don't think all authors use the exact same definition.

Phenotypic plasticity


  Phenotypic plasticity refers to the changes in an organism's behavior, morphology and physiology due to its adaption to a unique environment.2 Fundamental to the way in which organisms cope with environmental variation, phenotypic plasticity encompasses all types of environmentally induced changes (e.g. morphological, physiological, behavioural, phenological) that may or may not be permanent throughout an individual's lifespan. The term was originally used to describe developmental effects on morphological characters, but is now more broadly used to describe all phenotypic responses to environmental change, such as acclimation or acclimatization, as well as learning.5 The special case when differences in environment induce discrete phenotypes is termed polyphenism.


Exaptation

This is a poorly related term but it may eventually be of interest to you. The definition from wiki > Exaptation


  Exaptation [..] and the related term co-option describe a shift in the function of a trait during evolution. For example, a trait can evolve because it served one particular function, but subsequently it may come to serve another. Exaptations are common in both anatomy and behaviour. Bird feathers are a classic example: initially they may have evolved for temperature regulation, but later were adapted for flight. Interest in exaptation relates to both the process and products of evolution: the process that creates complex traits and the products (functions, anatomical structures, biochemicals, etc.) that may be imperfectly developed.


Phylogenetic signal

Phylogenetic signal is used way more often than the term exaptation. It is however also quite unrelated to what you are looking for but I added it because... well we never know what you'll find helpful!


  Phylogenetic signal is a measure of the statistical dependence among species' trait values due to their phylogenetic relationships.


For example, the existence of 4 limbs in vertebrates is a phylogenetic signal (see Why don't mammals have more than 4 limbs?)