- A measurement is presented of electroweak (EW) production of a ; W; boson in association with two jets in proton-proton collisions at ; ; ; s; ; =; 13; ; ; Te; ; ; ; . The data sample was recorded by the CMS Collaboration at the LHC and corresponds to an integrated luminosity of 35.9 ; ; ; ; fb; ; -; 1; ; ; ; . The measurement is performed for the ; ; ℓ; ν; ; jj final state (with ; ; ℓ; ν; ; indicating a lepton-neutrino pair, and j representing the quarks produced in the hard interaction) in a kinematic region defined by invariant mass ; ; ; m; jj; ; >; 120; ; ; Ge; ; ; ; and transverse momenta ; ; ; p; ; T; j; ; ; >; 25; ; ; Ge; ; ; ; . The cross section of the process is measured in the electron and muon channels yielding ; ; ; σ; EW; ; ; (; W; jj; ); ; =; 6.23; ±; 0.12; ; (stat); ±; 0.61; ; (syst); ; pb; ; per channel, in agreement with leading-order standard model predictions. The additional hadronic activity of events in a signal-enriched region is studied, and the measurements are compared with predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. Limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are ; ; -; 2.3; <; ; c; ; W; W; W; ; ; /; ; Λ; 2; ; <; 2.5; ; ; ; Te; ; ; ; -; 2; ; ; ; , ; ; -; 8.8; <; ; c; W; ; /; ; Λ; 2; ; <; 16; ; ; ; Te; ; ; ; -; 2; ; ; ; , and ; ; -; 45; <; ; c; B; ; /; ; Λ; 2; ; <; 46; ; ; ; Te; ; ; ; -; 2; ; ; ; . These results are combined with the CMS EW ; Zjj; analysis, yielding the constraint on the ; ; c; ; W; W; W; ; ; coupling: ; ; -; 1.8; <; ; c; ; W; W; W; ; ; /; ; Λ; 2; ; <; 2.0; ; ; ; Te; ; ; ; -; 2; ; ; ; .