Synonyms for Streamlined (same or very similar meaning)
WordNet sense 1 (designed or arranged to offer the least resistant to fluid flow):
aerodynamic, flowing, sleek
WordNet sense 2 (having a surface free from roughness or bumps or ridges or irregularities):
smooth
WordNet sense 3 (being effective without wasting time or effort or expense):
efficient
From the ODE community, based on WordNet
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