Definition of microtunnelling in English:
microtunnelling
noun ˌmʌɪkrə(ʊ)ˈtʌn(ə)lɪŋ
The formation or construction of extremely small-diameter tunnels, especially (in Engineering) the mechanical excavation of such tunnels, which are typically used for pipe-laying.
adjective ˌmʌɪkrə(ʊ)ˈtʌn(ə)lɪŋ
Of, relating to, or designating the formation or construction of very small-diameter tunnels or channels, especially (in Engineering) the mechanical excavation of such tunnels, e.g. for pipe-laying. Usually attributive.
Origin
1980s; earliest use found in Soviet Materials Science. From micro- + tunnelling
1980s; earliest use found in Japan Telecommunications Review. From microtunnelling; compare -ing.
Definition of microtunnelling in US English:
microtunnelling
nounˌmʌɪkrə(ʊ)ˈtʌn(ə)lɪŋ
The formation or construction of extremely small-diameter tunnels, especially (in Engineering) the mechanical excavation of such tunnels, which are typically used for pipe-laying.
adjectiveˌmʌɪkrə(ʊ)ˈtʌn(ə)lɪŋ
Of, relating to, or designating the formation or construction of very small-diameter tunnels or channels, especially (in Engineering) the mechanical excavation of such tunnels, e.g. for pipe-laying. Usually attributive.
Origin
1980s; earliest use found in Soviet Materials Science. From micro- + tunnelling<br>1980s; earliest use found in Japan Telecommunications Review. From microtunnelling; compare -ing.