'En route' means:

Foreign words are those words that have roots from other languages or Simply we can define it as a word that is adopted from other language. They are normally written in Italics to identify that they are foreign. Most of these foreign words are taken from latin.

1. ab incunabulis: from the cradle
2. a bon chat, bon rat: to a good cat, a good rat (retaliation in kind)
3. a bouch ouverte: with open mouth (eagerly, uncritically)
4. ab ovo usque ad mala: from egg to apples (from beginning to end)
5. a bras ouverts: with open arms
6. ab uno disce omnes: from one learn to know all
7. a coup sur: with sure stroke (surely)
8. acte gratuit: gratuitous impulsive act
9. ad arbitrium: at will (arbitrarily)
10. ad extremum: to the extreme (at last)
11. ad majorem Dei gloriam: to the greater glory of God
12. ad patres: to his fathers (deceased)
13. ad unguem: to the fingernail (exactly)
14. ad utrumque paratus: prepared for either event
15. aegri somnia: a sick man’s dreams
16. aequam servare mentem: to preserve a calm mind
17. aequo animo: with even mind (calmly)
18. aere perennius: more lasting than bronze
19. a huis clos: with closed doors
20. a l’abandon: carelessly
21. a la belle etoile: under the beautiful star (in the open air at night)
22. a la bonne heure: at a good time (all right)
23. a la page: at the page (up to the minute)
24. alter idem: another self
25. a maximis ad minima: from the greatest to the least
26. a marveille: marvelously
27. amicus humani generis: friend of the human race
28. amicus usque ad aras: a friend as far as to the alters (a friend to the last extremity)
29. ami de cour: court friend
30. armamentum ad baculum: argument of the staff (appeal to force)
31. arrectis auribus: with ears pricked up
32. a torte et a travers: wrong and crosswise (without rhyme or reason)
33. au bout de son latin: at the end of one’s Latin (at the end of one’s mental resources)
34. au fait: to the point (socially correct)
35. au grand serieux: in all serious
36. au mieux: on the best terms (on intimate terms)
37. aurea mediocritas: the golden mean
38. auspicium melioris aevi: an omen of a better age
39. ausssitot dit, aussitot fait: no sooner said than done
40. autres temps, autres moeurs: other times, other customs
41. aut vincere aut mori: either to conquer or to die
42. bellum omnium contra onnes: war of all against all
43. bien-pensant: right minded (orthodox)
44. bon gre, mal gre: whether with good grace or bad (willy-nilly)
45. bonis avibus: under good auspices
45. brutum fulmen: insensible thunderbolt (futile threat of display of force)
47. cadit quaestio: the question drops (the argument collapses)
48. capable de tout: capable of anything (unpredictable)
49. cause sine qua non: an indispensable cause or condition
50. cheval de bataille: war-horse (argument constantly relied on)
51. comedie humaine: human comedy (the whole variety of human life)
52. comedie larmoyante: tearful comedy (sentimental comedy)
53. comagnon de voyage: traveling companion
54. compte rendu: report
55. concordia discors: discordant harmony
56. confessio fidei: confession of faith
57. contemptus mundi: contempt for the world
58. coup de maitre: masterstroke
59. coup d’essai: experiment
60. coute que coute: cost what it may
61. cri de coeur: cry of the heart
62. crise de conscience: crisis of conscience
63. crise de nerfs: crisis of nerves
64. crux criticorum: crux of critics
65. cum grano salis: with a grain of salt
66. custos morum: guardian of morals (censor)
67. de bonne grice: with good grace
68. de l’audace, encore de l’audace, et toujours de l’audace: audacity, more audacity, and ever more audacity
69. de mal en pis: from bad to worse
70. Deo favente: with God’s favor
71. de profundis: out of the depths
72. desipere in loco: to indulge in trifling at the proper time
73. Deus absconditus: hidden God (unknowable God)
74. dies faustus: lucky day
75. dies infaustus: unlucky day
76. dies irae: day of wrath
77. esprit d’le escalier: the wit of the staircase
78. faux bonhomme: false friend
79. faux-naif: affectedly simple or childlike
80. festina lente: make haste slowly
81. feux d’artifice: fireworks, or show of wit
82. folie de grandeur: delusion of greatness, megalomania
83. furor loquendi: rage for speaking
84. furor poeticus: rage for poetry
85. furor scribendi: rage for writing
86. gens du mond: fashionable people
87. guerre a outrance: war to the uttermost
88. haut gout: slight taint of decay
89. hic illae lacrimae: hence these tears
90. homme d’esprit: witty man
91. in omnia paratus: ready for all things
92. in partibus infidelium: in the land of the infidels
93. in statu quo ante bellum: just like before the war
94. januis clausis: behind closed doors
95. jeu de mots: play on words
96. ktema es ai: a possession for ever (enduring art or literature)
97. la belle dame sans merci: the beautiful lady without mercy
98. lacrimae rerum: tragedy of life
99. lapsus calami: slip of the pen
100. lapsus linguae: slip of the tongue