ˈmakrōˌsīzəm sometimes -sez- or -sāz- or -sēz- noun
Etymology: International Scientific Vocabulary macr- + -seism
: a severe or major earthquake — compare microseism
• mac·ro·seis·mic |makrō|sī]zmik also ]sm- sometimes -|se] or -|sā] or -|sē]\ adjective